Memory circuits have been used in various applications. Conventionally, memory circuits can include dynamic random access memory (DRAM) circuits, static random access memory (SRAM) circuits, and non-volatile memory circuits. A SRAM circuit includes a plurality of memory cells. For a conventional 6-T SRAM circuit in which arrays of memory cells are provided, each of the memory cells has six transistors. The 6-T SRAM memory cell is coupled with a bit line BL, a bit line bar BLB, and a word line WL. Four of the six transistors form two cross-coupled inverters for storing a datum representing “0” or “1”. The remaining two transistors serve as access transistors to control the access of the datum stored within the memory cell.